Research And Analysis On Dynamic Characteristic Of Two-axle Vehicle With Large Tonnage

Nowadays, the application of the engineering vehicles with the demand ofproduction and construction is more and more widely and its development directiontoward uncertainty road conditions, large-tonnage and high speed. When theperformance of the suspension is poor and road condition is intensely bumpy, thevehicle has to drive at low speed. So the handling stability and riding comfort of thevehicles is directly influence by the performance of the suspension. The subject ofthis paper comes from the technical project of Chongqing Dajiang Xinda VehicleCompany Limited. Aiming at the characteristic of the two-axle vehicle with largetonnage, a new improved hydro-pneumatic suspension with the interconnection typeabout right and left was built and combined with Matlab and AMEsim software, itsmathematical model and simulation model was established and analyzed.The new improved hydro-pneumatic suspension with the interconnection typeabout right and left aimed to meet space limitation and the riding comfort andoperation stability. The following several aspects work was finished for this topic.1. In order to satisfy the special requirements of space constraints for thetwo-axle vehicle with large tonnage, the improvement of the double chamberstructure was adopted for the interconnect hydro-pneumatic suspension. For thesake of avoiding the phenomenon of bumping of cylinder in stretching the schedule,and effectively use of space to reduce the size of the suspension, the structure whichcan not only satisfy the stability and comfort but also can realize compact spaceconstraints combined built-in accumulator with external accumulator was cited2. The parallel built-in damping hole was used on the suspension piston rod tobetter absorb the damping when the suspension cylinder scaling back and forth. Thecompensation chamber was designed on the top of the piston to ensure that the pistonpressure can keep balance in the static. The pressure control tracker was designed toimprove body jitter caused by the bad load resistance of the accumulator.3. Based on the improved hydro-pneumatic suspension, the mathematical modelwas established and the main parameters affecting mathematical model wasdetermined by analyzing its basic structure and principle. The simulation model of theimproved interconnection hydro-pneumatic suspension was built by using theAMESim. In view of the particularity of the improved hydro-pneumatic suspension cylinder, the hydro-pneumatic suspension cylinder and the pressure trackingcontroller were designed in the hydraulic components design repository (HCD).Finally, the correctness of the output force characteristics, stiffness characteristics andthe damping characteristics were verified according to the mathematical model andsimulation model.4. Basing on the simulation model, the curves of displacement and velocity ofinterconnected hydro-pneumatic suspension cylinder were analyzed and factors thataffected the damping and stiffness characteristics of this simulation model werereviewed in this paper. The structure model and operating principle of the pressuretracking controller were introduced. The code of setting the parameter of the pressuretracking controller was compiled and the improved structures affecting the ridequality were analyzed. The result indicated that the improved interconnectedhydro-pneumatic suspension met the requirement of space constraints of two-axlevehicle with large tonnage, and that response time of the vertical displacement andacceleration of the vehicle was shorted obviously and the ability to adjust fluctuationwas significantly improve.